They accused companies offering “health MOTs” — an industry worth more than £100 million a year — of using questionable tactics by targeting the “worried well” and making people pay for tests they do not need.

Stroke expert Dr Tony Rudd said some firms were offering tests for the condition without proper medical justification. Dr Rudd, consultant stroke physician at Guy’s and St Thomas’ NHS trust, said: “If you have had any symptoms, yes you definitely need a scan.

“You need that scan very urgently and the NHS is perfectly well equipped to provide that. If you haven’t had any symptoms at all, then the risk of having a stroke is very, very low. And therefore screening is not really necessary.”

Nicholas Nicolaou, 50, of Enfield, told how he got a letter from a company outlining his potential risk of cardiovascular disease, and showing images of blocked arteries. He said the firm ap-peared to have knowledge of his medical history, as his father died of a stroke, so he booked a £200 screening.

He said: “The results were nothing special, although it was good that there was nothing wrong with me. The GP looked at them and said there is nothing there we haven’t done already. In other words, I’ve just wasted my time.”

A BBC Inside Out investigation found eight out of 10 health screening companies they contacted were happy to book a reporter for tests, even though they were not displaying symptoms of disease and were under the age at which most screenings are considered necessary by the NHS. The tests ranged from £100 to several thousand pounds.

Epsom GP Pete Deveson said: “A leaflet in my door said your risk of stroke is one in five in your lifetime. There is no one in my house over 35, so our risk as healthy non-smokers in the next 10 years is probably 1 in 200 to 1 in 1,000.” Dr Anne Mackie of the UK National Screening Committee said: “The tests aren’t terribly accurate: you might find an abnormality but be alright, or might find no abnormality and not be OK.”